Portable information terminals, typified by portable telephone units, PDAs (Personal Digital Assistants), and personal organizers, are generally provided with a display section that is, for example, a liquid crystal display screen that displays text and images; and an input section through which the user inputs commands and data.
Some of portable information terminals use a touch panel type input section. For example, Patent Literature 1 discloses an information terminal that uses a touch panel type input section. The touch panel type input section can increase the display size relative to the device size compared to the case in which a display section and an input section are arranged at different positions.
On the other hand, some of portable information terminals are provided with a display section having a plurality of display screens. For example, a portable information terminal provided with foldable housings each having a display screen has characteristics in which, when used in the folded state, it is small and portable and when used in the spread state, it provides a large screen.
A portable information terminal provided with a plurality of display screens has a boundary that lies therebetween. Thus, if one original image is displayed on a plurality of display screens, since the boundary divides the image into two portions, the image becomes illegible.
Patent Literature 2 discloses a technique that divides one original image into two portions and displays them on two display screens. The technique disclosed in Patent Literature 2 changes the display style of an image depending on its type so as to alleviate such illegibility. The technique disclosed in Patent Literature 2 does not display an original image that lies at the boundary on any one of the two display screens if the image is graphic data, but displays an original image that lies at the boundary portion on any one of the two display screens if the original image is text data.
Patent Literature 3 discloses a technique that improves the visibility of an image on a display screen. The technique disclosed in Patent Literature 3 improves the visibility of a portion of an image that the user wants to watch in such a manner that he or she designates the range of the image to be enlarged. When the user touches two points on a touch panel for a predetermined period of time, the range is designated. When the user slides the two points that he or she is touching, the designated portion is enlarged.